Tertiary butyl alcohol as a tubing fluid



United States Patent TERTIARY sUrYL ALCOHOL As A TUBING FLUID Gilbert B. Ayres, Pearl River, N. Y., assignor to Davis & Geek, Inc., Danbury, COIIIL, a corporation of New York No Drawing. Application July 31, 1953, Serial No. 371,713

1 Claim. (Ci. 2063.3)

This invention relates to surgical sutures of the proteinaceous type and, more particularly, to the preservation and conditioning of non-boilable surgical sutures. Still more particularly, this invention relates to a method of improving the flexibility and strength of catgut sutures while reducing swelling, and to the composition of the liquid in which non-boilable catgut sutures are customarily packaged or tubed.

The present invention is based upon my discovery that tertiary-butyl alcohol, either pure or containing a small quantity of water, exhibits certain unexpected properties when in contact with catgut sutures that makes it highly desirable for use as a tubing fluid.

In the process of preparing catgut for suture use it is customary, usually as a final step, to expose the gut to a high temperature as, for example, from 230 F. to 300 F. in order to produce a sterile suture. Before this can be accomplished, however, the gut must be thoroughly dried or dehydrated for the reason that the presence of water at such temperatures lessens the strength of the suture and may even reduce it to an incoherent, jelly-like mass. The suture may be heat-sterilized in a dry condition, i. e. in the absence of any liquid, or it may be sterilized by heating in a liquid inert to the suture such as xylene, toluol or the like. In either event, the suture immediately after sterilization is hard, stiff and brittle and is in no condition to be used. It is, therefore, customary to package sterile sutures in sealed glass tubes together with a fluid called tubing fluid. This may be identical with or similar to the fluid in which the suture was sterilized, in which event the tube with the suture and the liquid sealed inside is labeled boilable; or it may be a diflerent fluid or solution which reacts with the gut of the suture to soften and flexibilize it, in which event the suture is labeled non-boilable.

Each of the above sutures has its own advantages and disadvantages. Boilable sutures have the advantage that the tube containing the suture may be boiled (sterilized) immediately before removal of the suture to avoid danger of contamination by contact of the suture with the outside walls of the tube during removal of the suture. This procedure is sometimes necessary to insure prevention of infection of the tissue into which the suture comes in contact and is in accordance with the high standards of surgical practice. A disadvantage accompanying the use of such sutures is that they must be soaked in water or other conditioning solution under aseptic conditions to soften and flexibilize them before they can be used.

Non-boilable sutures, however, are softened and flexibilized by the liquid in the tube and are available for use substantially immediately upon removal. The disadvantage due to the non-boilability of the suture has in part been obviated by packaging it in two or more sealed, sterile containers, with the tube or ampoule containing the suture being the innermost container.

While non-boilable sutures are much to be preferred over boilable sutures for the reason that they can be used immediately, their use has been hampered by the inability of the known tubing fluids to provide a suture having optimum flexibility, softness and strength. The exact mechanism by which the fluid or solution softens and flexibilizes the gut is not known. The protein of which gut is composed is exceedingly complex and highly reactive and its characteristics are variously changed and modified, depending upon the materials and conditions to which it is subjected.

Therefore, many factors are involved in meeting the requirements of a suitable tubing fluid for non-boilable surgical gut sutures. It is important, for instance, that the fluid have no deleterious effect on the protein of the suture at the temperatures involved it should be soluble in Water and non-irritating to the tissue with which it will come in contact in use and it should have antiseptic properties. Swelling of the suture caused by the fluid should be kept at a minimum and suture strength and flexibility and softness maintained at a maximum. Odor is also an important factor from the marketability and handling aspect and it should not be disagreeable.

I have discovered that tertiary-butyl alcohol is nondestructive toward catgut sutures and that in admixture with up to 15% of water it can be used for tubing nonboilable sutures with the securing of advantages not heretofor possible with water-containing tubing fluids of the prior art such as ethyl alcohol and water, methyl alcohol and water or propyl or isopropyl alcohol and water. Using, for instance, a mixture containing tertiary butyl alcohol and 10% water as a tubing fluid, I have found that the swelling of catgut sutures is about one-half as great when a 90% isopropanol-water solution is used and about one-fourth as much as when the suture is tubed in ethanol-water solution. The tensile strength of the suture per unit of cross-sectional area is thus substantially increased which is much to be desired. In addition, the suture has maximum flexibility.

I have further discovered that tertiary-butyl alcohol in the anhydrous condition is non-destructive to catgut sutures even at boiling or sterilizing temperatures and may be used as an excellent tubing fluid for boilable sutures even though it solidifies at 25.6 C. Solidification appears to have no ill eflects on the suture, and the alcohol being miscible in all proportions in water is quickly removed on soaking.

The mixture of tertiary butyl alcohol and water of the present invention provides an excellent fluid for tubing non-boilable surgical sutures both with and without needles attached. Phenyl-mercuric benzoate or other suitable antiseptic may be added to the solution if desired in order to reduce the possibility of contaminating the catgut once it has been sterilized.

I claim:

As an article of manufacture, a sealed container hav ing therein in combination, a proteinaceous suture and a tubing fluid consisting essentially of tertiary butyl alco hol and water.

References Cited in the file of this patent UNITED STATES PATENTS 2,519,404 Rynkiewicz Aug. 22, 1950 

